Hard disk drives are used in almost all computer system operations. In fact, most computing systems are not operational without some type of hard disk drive to store the most basic computing information such as the boot operation, the operating system, the applications, and the like. In general, the hard disk drive is a device which may or may not be removable, but without which the computing system will generally not operate.
The basic hard disk drive model was established approximately 50 years ago and resembles a phonograph. That is, the hard drive model includes a storage disk or hard disk that spins at a standard rotational speed. An actuator arm with a suspended slider is utilized to reach out over the disk. The arm carries a head assembly that has a magnetic read/write transducer or head for reading/writing information to or from a location on the disk. The complete head assembly, e.g., the suspension and head, is called a head gimbal assembly (HGA).
In operation, the hard disk is rotated at a set speed via a spindle motor assembly having a central drive hub. Additionally, there are tracks evenly spaced at known intervals across the disk. When a request for a read of a specific portion or track is received, the hard disk aligns the head, via the arm, over the specific track location and the head reads the information from the disk. In the same manner, when a request for a write of a specific portion or track is received, the hard disk aligns the head, via the arm, over the specific track location and the head writes the information to the disk.
Over the years, the disk and the head have undergone great reductions in their size. Much of the refinement has been driven by consumer demand for smaller and more portable hard drives such as those used in personal digital assistants (PDAs), MP3 players, and the like. For example, the original hard disk drive had a disk diameter of 24 inches. Modern hard disk drives are much smaller and include disk diameters of less than 2.5 inches (micro drives are significantly smaller than that). Advances in magnetic recording are also primary reasons for the reduction in size.
However, the decreased track spacing and the overall reduction in HDD component size and weight have resulted in problems with respect to the electrical lead suspension (henceforth referred to as ELS), used in a Data Access Storage Device (DASD), e.g., a hard disk drive (HDD). For example, a typical ELS is formed from a laminate comprised of at least three layers of material. These laminate layers may include a signal-conductor layer from which signal traces are formed, a dielectric layer for insulation supporting the signal-conductor layer, and a conductive base-metal layer supporting the dielectric layer.
Prior Art FIG. 1 is a top plan view 100 of an ELS tail portion having write traces 120 and read traces 130 formed from the signal-conductor layer above a laminate dielectric layer. The dielectric layer is provided above the base-metal layer of the laminate. The supporting base-metal layer is formed having continous airslots under the read 130 write 120 pairs, so as to allow the head to fly properly and providing the necessary amount of mechanical stiffness for supporting the signal traces 120 and 130 that are the read and write traces. While the slotted base-metal layer can provide the appropriate mechanical stiffness, this metal layer and continous airslots underneath the read and write traces 120 and 130 results in write-to-read cross-talk that degrades the performance of the read sensor. For example, the read traces 130 connect to a voltage-sensitive read sensor. However, the write driver utilizes a large voltage to produce a current in the write traces 120 that will interact with the base-metal layer 110 and produce a current in read traces 130. This production of non-desired current in read traces 130 from the voltage applied to write traces 130 is detrimental to the overall function of the ELS. Moreover, as the size of the ELS is reduced, the amount of voltage required by the write traces 120 to cause interference with the read traces 130 is also reduced.